It's confirmed. Lloyd Blankfein will testify at the trial of Raj Rajaratnam for insider trading, according to letters sent to Judge Holwell, from government prosecutors and Raj's defense (via Bloomberg).

Whether or not Goldman CEO Lloyd Blankfein will testify at the Raj trial has been speculated about for weeks. Now, we know he will.

And according to the letter from the attorneys representing Raj, it could be as early as this week.

Interestingly, the prosecution wrote the letter out of concern that Raj's defense might try to impeach Blankfein by bringing up Goldman's involvement in the financial crisis and its current (and many) legal proceedings.

Important details from the letter:

1. The U.S. government will call Lloyd Blankfein to testify.

2. The government doesn't want the defense to bring up “whether Goldman Sachs is presently the subject of any pending investigations by either the Department of Justice or the U.S. Securities and Exchange Commission” OR whether Goldman Sachs bears any responsibility for the 2008 financial crisis in their cross examination during their cross-examination for the government's witness on some unknown date.

3. The Raj defense is only trying to bring up both Goldman Sachs' legal proceedings and their involvement in the financial crisis in order to impeach Blankfein, according to the prosecution.

From the prosecution's letter:

These [legal] proceedings are not relevant... The only conceivable relevance would be general impeachment of Mr. Blankfein. Rajaratnam might suggest, for example, that because Goldman Sachs is tied up in many different legal proceedings, the firm—and by extension its CEO, Blankfein—is not to be trusted. But this claim is totally unfounded and would threaten confusion of the issues.